“On flat surfaces with no objects in their path, wheeled robots
are more efficient than tracked, legged, and even aerial robots.
In sand, mud, and rougher terrain, tracks are superior to wheels.
However, with fixed objects, obstacles, and vertical surfaces in
the path of a tracked robot with no alternative path, legged robots
are superior. Even if moderate objects and obstacles can be overcome
by tracks, continuous unstructured terrain over a large field of
operation reduces the energy efficiency of tracked devices when
compared to dynamic legged robots.”